About Rule Terminology and Concepts

A rule project is a container for rule code. GE Digital APM uses two types of rule projects:

• Family Rule Project: Stores all the rules for a given family.
• Rules Library Project: Stores all the rules that exist for that project.

Rule projects contain references and files, also called code items. The files contain rules that are defined for that project. The file structure for family projects is determined by the content of the family. The file structure of a Rules Library project is determined by the project owner and can be customized as necessary to meet the requirements of the project.

A class is a VB.Net element that serves as a container for storing objects. Classes are defined within the files that exist in a rule project.

• In family rule projects, GE Digital APM automatically defines classes within the files that exist for the family itself and the fields within that family.
• In baseline Rules Library projects, classes serve as containers for the code within those projects.
• In custom Rules Library projects, you can define your own classes as needed. When you create a new project, one file will be created within that project, and within that file, a default class will be defined.

Any VB.Net class can be inherited from another class so that the rules defined in one class can be reused as often as needed.

The following code excerpt shows an example of the default class Class1 that is created when you create a new Rules Library project:

                        Option Strict On
                    

                        Option Explicit On
                    

                        Imports Meridium.Core.DataManager

                        Imports Meridium.Core.DataManager.Customization

                        Imports Meridium.Core.Internals

                        Imports Meridium.Core.Metadata

                        Imports Meridium.Core.Security.ApplicationUser

                        Imports Meridium.Core.Uom

                        Imports System

                        Imports System.Xml

                        Public Class Class1

    Private Sub New()

        MyBase.New

        '

        'TODO: Add constructor logic here

        '

    End Sub

                        End Class
                    

In this example, the lines Public Class Class1 and End Class define the class; the code in between these two lines of text represents all the objects that belong to the class.

A function is a block of rule code that defines a Function procedure. Functions can be defined to invoke specific behaviors. The standard field-level rules that are available in GE Digital APM are defined through functions. In the following example, the IsRequired function is between the two lines Public Class Class1 and End Class.

                        Option Strict On
                    

                        Option Explicit On
                    

                        Imports Meridium.Core.DataManager

                        Imports Meridium.Core.DataManager.Customization

                        Imports Meridium.Core.Internals

                        Imports Meridium.Core.Metadata

                        Imports Meridium.Core.Security.ApplicationUser

                        Imports Meridium.Core.Uom

                        Imports System

                        Imports System.Xml

                        Public Class Class1

    Public Overrides Function IsRequired() As Boolean

        Return True

    End Function

                        End Class
                    

Inheritance allows one class to use the behaviors defined in another class.

• The class that is inherited is considered the base class and serves as a foundation for the functionality of the class that inherits it.
• Any class that inherits from another class is considered a derived class.

All the functions and behaviors defined in the base class are automatically applied to the derived class. Within the derived class, code can be written to extend or override specific functions defined in the base class. Inheritance allows you to create new classes based on existing classes and is an important component of the Rules Library and baseline rule storage.

Inheritance is achieved through an Inherits statement in the derived class. For instance, in the following example, the class MI_RCA_ANALY_COST_NBR (the derived class) inherits the class EntityFieldCustomization (the base class).

                        Public Class MI_RCA_ANALY_COST_NBR

    Inherits EntityFieldCustomization

                        End Class